Agilent 34401A
6 ½ Digit Multimeter
Service Guide
Agilent Technologies
Notices
© Agilent Technologies, Inc. 1991 - 2007
No p art o f this manual may be rep roduc ed in
any form or by any means (including electronic storage and retrieval or translation
into a foreign language) without prior agreement and written consent from Agilent
Technologies, Inc. as governed by United
States and international copyright laws.
Manual Part Number
34401-90013
Edition
Seventh Editio n. August 2007
Printed in Malaysia
Agilent Technologies, Inc.
3501 Stevens Creek Blvd.
Santa Clara, CA 95052 USA
Microsoft® and Windows® are U.S. registered trademarks of Microsoft Corporation.
Software Revision
This guide is valid for the firmware that was
installed in the instrument at the time of
manufacture. However, upgrading the firmware may add or change product features.
For the latest firmware and documentation,
go to the product page at:
www.agilent.com/find/34401A
Warranty
The material contained in this document is provided “as is,” and is subject to being changed, without notice,
in future editions. Furt her, to the maximum extent permitted by applicable
law, Agilent disclaims all warranties,
either express or implied, with regard
to this manual and any information
contained herein, including but not
limited to the implied warranties of
merchantability and fitness for a particular purpose. Agilent shall not be
liable for errors or for incidental or
consequential damages in connection with the furnishing, use, or performance of this document or of any
information contained herein. Should
Agilent and the user have a separate
written agreement with warranty
terms covering the material in this
document that conflict with these
terms, the warranty terms in the separate agreement shall control.
Technology Licenses
The hardware and/or software described in
this document are furnished under a license
and may be used or copied only in accordance with the terms of such license.
Restricted Rights Legend
U.S. Government Restricted Rights. Software and technical data rights granted to
the federal government include only those
rights customarily provided to end user customers. Agilent provides this customary
commercial license in Software and technical data pursuant to FAR 12.211 (Technical
Data) and 12.212 (Computer Software) and,
for the Department of Defense, DFARS
252.227-7015 (Technical Data - Commercial
Items) and DFARS 227.7202-3 (Rights in
Commercial Computer Software or Computer Software Documentation).
Safety Notices
CAUTION
A CAUTION notice denotes a haz-
ard. It calls attention to an operating procedure, practice, or the like
that, if not correctly performed or
adhered to, could result in damage
to the product or loss of important
data. Do not proceed beyond a
CAUTION notice until the indicated
conditions are fully understood and
met.
WARNING
A WARNING notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly performed or adhered to, could result
in personal injury or death. Do not
proceed beyond a WARNING
notice until the indicated conditions are fully understood and
met.
ii 34401A Service Guide
Safety Information
General
Do not use this product in any manner not
specified by the manufacturer. The protective features of this product may be
impaired if it is used in a manner not specified in the operation instructions.
Do not install substitute parts or perform
any unauthorized modification to the product. Return the product to an Agilent Technologi es Sales and S ervice Office for service
and repair to ensure that safety features are
maintained.
Ground the Instrument
If your product is provided with a grounding-type power plug, the instrument chassis
and cover must be connected to an electrical ground to minimize shock hazard. The
ground pin must be firmly connected to an
electrical ground (safety ground) terminal at
the power outlet. Any interruption of the
protective (grounding) conductor or disconnection of the protective earth termin al will
cause a potential shock hazard that could
result in personal injury.
Cleaning
Clean the outside of the instrument with a
soft, lint-free, slightly dampened cloth. Do
not use detergent or chemical solvents.
Safety Symbols
Earth Ground
Chassis Ground
Risk of electric shock
Refer to manual for additional safety information
Alternating Current
On supply
Off supply
‘In’ position of bi-stable push
switch
‘Out’ position of bi-stable
push switch
CAT II (300V)
IEC Measurement Category II.
Inputs may be connected to
mains (up to 300 VAC) under
Category II overvoltage conditions.
WARNING
Main Power and Test Input Disconnect: Unplug instrument from
wall outlet, remove power cord,
and remove all probes from all
terminals before servicing. Only
qualified, service-trained personnel should remove the cover from
the instrument.
WARNING
Line and Current Protection
Fuses: For continued protection
against fire, replace the line fuse
and the current-protection fuse
only with fuses of the specified
type and rating.
WARNING
Front/Rear Switch: Do not
change the position of the
Front/Rear switch on the front
panel while signals are present on
either the front or rear set of terminals. The switch is not intended
as an active multiplexer. Switching while high voltages or currents are present may cause
instrument damage and lead to
the risk of electric shock.
34401A Service Guide iii
WARNING
IEC Measurement Category II. The
HI and LO input terminals may be
connected to mains in IEC Category II installations for line voltages up to 300 VAC. To avoid the
danger of electric shock, do not
connect the inputs to mains for
line voltages above 300 VAC. See
"IEC Measurement Category II
Overvoltage Protection" on the
following page for further information.
WARNING
Protection Limits: To avoid instrument damage and the risk of electric shock, do not exceed any of
the Protection Limits defined in
the following section.
Protection Limits
The Agilent 34401A Digital Multimeter provides protection circuitry to prevent damage
to the instrument and to protect against the
danger of electric shock, provided the Protection Limits are not exceeded. To ensure
safe operation of the instrument, do not
exceed the Protection Limits shown on the
front and rear panel, and defined as follows:
Note: The front-panel terminals are shown
above. The rear-panel terminals are identical. The Front/Rear switch selects the terminal set to be used. Do not operate this
switch while signals are pr esent on the
front or rear terminals. The current-protec-
tion fuse is on the rear panel.
Input Terminal Protection
Limits
Protection Limits are defined for the input
terminals:
Main Input (HI and LO) Terminals. The HI
and LO input terminals are used for voltage,
resistance, frequency (period), and diode
test measurements. Two Protection Limits
are defined for these terminals:
HI to LO Protection Limit. The Protection
Limit from HI to LO (Input terminals) is
1000 VDC or 750 VAC, which is also the
maximum voltage measurement. This
limit can also be expressed as 1000 Vpk
maximum.
LO to Ground Protection Limit. The LO
input terminal can safely "float" a maximum of 500 Vpk relative to ground.
As is implied by the above limits, the Protection Limit for the HI input terminal is a maximum of 1500 Vpk relative to ground.
Current Input Terminal. The current input
("I") terminal has a Protection Limit of 3A
(rms) maximum current flowing from the LO
input terminal. Note that the current input
terminal will be at approximately the same
voltage as the LO terminal.
Note: The current-protection circuitry
includes a fuse on the rear panel. To maintain protection, replace this fuse only with a
fuse of the specified type and rating.
Sense Terminal Protection
Limits
The HI and LO sense terminals are used
only for four-wire resistance and temperature measurements ("
tion Limit is 200 Vpk for all of the terminal
pairings:
LO sense to LO input
HI sense to LO input
HI sense to LO sense
Note: The 200 Vpk limit on the sense terminals is the Protection Limit. Operational
voltages in resistance measurements are
much lower — less than 10 V in normal
operation.
Ω 4W"). The Protec-
IEC Measurement Category II
Overvoltage Protection
To protect against the danger of electric
shock, the Agilent 34401A Digital Multimeter provides overvoltage protection for
line-voltage mains connections meeting
both of the following conditions:
The HI and LO input terminals are connected to the mains under Measurement
Category II conditions, defined below,
The mains are limited to a maximum line
voltage of 300 VAC.
and
iv 34401A Service Guide
IEC Measurement Category II includes electrical devices connected to mains at an outlet on a branch circuit. Such devices include
most small appliances, test equipment, and
other devices that plug into a branch outlet
or socket. The 34401A may be used to make
measurements with the HI and LO inputs
connected to mains in such devices, or to
the branch outlet itself (up to 300 VAC).
However, the 34401A may not be used with
its HI and LO inputs connected to mains in
permanently installed electrical devices
such as the main circuit-breaker panel,
sub-panel disconnect boxes, or permanently
wired motors. Such devices and circuits are
subject to overvoltages that may exceed the
protection limits of the 34401A.
Note: Voltages above 300 VAC may be measured only in circuits that are isolated from
mains. However, transient overvoltages are
also present on circuits that are isolated
from mains. The Agilent 34401A are
designed to safely withstand occasional
transient overvoltages up to 2500 Vpk. Do
not use this equipment to measure circuits
where transi ent overvoltages could exceed
this level.
Additional Notices
Waste Electrical and
Electronic Equipment (WEEE)
Directive 2002/96/EC
This product complies with the WEEE Directive (2002/96/EC) marking requirement.
The affixed product label (see below) indicates that you must not discard this electrical/electronic product in domestic
household waste.
Product Category: With reference to the
equipment types in the WEEE directive
Annex 1, this product is classified as a
"Monitoring and Contr ol instrumentation"
product.
Do not dispose in domestic household
waste.
To return unwanted products, contact your
local Agilent office, or see
www.agilent.com/environment/product
for more information.
Agilent 34138A Test Lead Set
The Agilent 34401A is compatible with the
Agilent 34138A Test Lead Set described
below.
Test L e a d Ra t i n g s
Test Leads - 1000V, 15A
Fine Tip Probe Attachments - 300V, 3A
Mini Grabber Attachment - 300V, 3A
SMT Grabber Attachments - 300V, 3A
Operation
The Fine Tip, Mini Grabber, and SMT Grabber attachments plug onto the probe end of
the Test Leads.
Maintenance
If any portion of the Test Lead Set is worn or
damaged, do not use. Replace with a new
Agilent 34138A Test Lead Set.
WARNING
If the Test Lead Set is used in a
manner not specified by Agilent
Technologies, the protection provided by the Test Lead Set may be
impaired. Also, do not use a damaged or worn Test Lead Set.
Instrument damage or personal
injury may result.
34401A Service Guide v
DECLARATION OF CONFORMITY
According to ISO/IEC Guide 22 and CEN/CENELEC EN 45014
Manufacturer’s Name:
Manufacturer’s Address:
Agilent Technologies, Incorporated
815 – 14th St. SW
Loveland, Colorado 80537
USA
Declares, that the product
Product Name:
Model Number:
Multimeter
34401A
Product Options: This declaration covers all options of the above product(s).
Conforms with the following European Directives:
The product herewith complies with the requirements of the Low Voltage Directive 73/23/EEC and the EMC Directive 89/336/EEC
(including 93/68/EEC) and carries the CE Marking accordingly.
Conforms with the following product standards:
EMC Standard
IEC 61326-1:1997+A1:1998 / EN 61326-1:1997+A1:1998
CISPR 11:1990 / EN 55011:1991
IEC 61000-4-2:1995+A1:1998 / EN 61000-4-2:1995
IEC 61000-4-3:1995 / EN 61000-4-3:1995
IEC 61000-4-4:1995 / EN 61000-4-4:1995
IEC 61000-4-5:1995 / EN 61000-4-5:1995
IEC 61000-4-6:1996 / EN 61000-4-6:1996
IEC 61000-4-11:1994 / EN 61000-4-11:1994
Canada: ICES-001:1998
Australia/New Zealand: AS/NZS 2064.1
Limit
Group 1 Class A
4kV CD, 8kV AD
3 V/m, 80-1000 MHz
0.5kV signal lines, 1kV power lines
0.5 kV line-line, 1 kV line-ground
3V, 0.15-80 MHz
Dips: 30% 10ms; 60% 100ms
Interrupt > 95%@5000ms
The product was tested in a typical configuration with Agilent Technologies test systems.
Safety
IEC 61010-1:1990+A1:1992+A2:1995 / EN 61010-1:1993+A2:1995
Canada: CSA C22.2 No. 1010.1:1992
UL 3111-1: 1994
18 July 2001
Date
Ray Corson
Product Regulations Program Manager
Authorized EU-representative: Agilent Technologies Deutschland GmbH, Herrenberger Straβe 130, D 71034 Böblingen, Germany
For further information, please contact your local Agilent Technologies sales office, agent or distributor.
Note: Unless otherwise indicated, this manual applies to all serial numbers.
The Agilent Technologies 34401A is a 6
1
⁄
-digit, high-performance
2
digital multimeter. Its co m bination o f bench-to p and syste m featur e s
makes this multimeter a versa t ile s olu t ion for y ou r meas u re men t need s
now and in the future.
Convenient Bench-Top Features
• Highly visible vacuum-fluoresc en t disp l ay
• Built-in math operations
• Continuity and diode test functions
• Hands-free, Reading Hold feature
• Portable, ruggedized case with non-skid feet
Flexible System Features
• GPIB (IEEE-488) interface and RS-232 interface
• Standard programming languages: SCPI, Agilent 3478A, and
Fluke 8840
• Reading rates up to 1000 readings per second
• Storage for up to 512 readings
Warning
• Limit testing with pass/fail signals
• Optional 34812A IntuiLink/Meter Software
®
for Microsoft
Windows
TM
The procedures in this manual are intended for u se by qualified,
service-trained personnel only.
Agilent 34401A
Multimeter
The Front Pa nel at a Glance
1 Measurement Function keys
2 Math Operation keys
3 Single Trigger / Autotrigger / Reading Hold key
4 Shift / Local key
2
5 Front / Rear Input Terminal Switch
6 Range / Number of Digits Displayed keys
7 Menu Operation keys
The Front-Panel Men u at a Glance
The menu is organized in a top -down tree structure with three levels.
A: MEASurement MENU
1: AC FILTER > 2: CONTINUITY > 3: INPUT R > 4: RATIO FUNC > 5: RESOLUTION
B: MATH MENU
1: MIN-MAX > 2: NULL VALUE > 3: dB REL > 4: dBm REF R > 5: LI MIT TEST > 6: HIGH LIMIT > 7: LOW LIMIT
C: TRIGger ME N U
1: READ HOLD > 2: TRIG DELAY > 3: N SAMPLES
D: SYStem MENU
1: RDGS STORE > 2: SAVED RDGS > 3: ERROR > 4: TEST > 5: DISPLAY > 6 : BEEP > 7: COMMA > 8 : REVISION
E: Input / Output MENU
1: HP-IB ADDR > 2: INTERFACE > 3: BAUD RATE > 4: PARITY > 5: LANGUAGE
F: CALibration MENU
1: SECURED > [ 1: UNSECURED ] > [ 2: CALIBRATE ] > 3: CAL COUNT > 4: MESSAGE
The commands enclosed in square brackets ( [ ] ) are “hidden” unless the multimeter
*
is UNSECURED for calibration.
*
3
Display Annunciators
∗
Adrs
Rmt
Man
Trig
Hold
Mem
Ratio
Math
ERROR
Rear
Shift
4W
Turns on during a measurement.
Multimeter is addressed to listen or talk over the GPIB interface.
Multimeter is in remote mode (remote interface).
Multimeter is using manual ranging (autorange is disabled).
Multimeter is waiting for a single trigger or external trigger.
Reading Hold is enabled.
Turns on when reading me mory is enabled.
Multimeter is in dcv:dcv ratio function.
A math operation is enabled (null, m in-max, dB, dBm, or limit test).
Hardware or remote interface command errors are detected.
Rear input terminals are selected.
“Shift” key has been pressed.
Multimeter is in 4-wire ohms function.
Multimeter is in continuity test function.
Multimeter is in diode test function.
Press “Shif t” again to tur n off.
To review the display annunciators, hold down the Shift key as you
turn on the multimeter.
4
The Rear Panel at a Glance
1 Chassis Ground
2 Power-Line Fuse-Holder Assembly
3 Power-Line Voltage Setting
4 Front and Rear Current Input Fuse
5 Voltmeter Complete Output Terminal
6 External Trigger Input Terminal
7 GPIB (IEEE-488) Interface connector
8 RS-232 interface connector
Use the front-panel Input / Output Menu to:
• Select the GPIB or RS-232 interface (see chapter 4 in the “User’s Guide”).
• Set the GPIB bus address (see chapter 4 in the “User’s Guide”).
• Set the RS-232 baud rate and parity (see chapter 4 in the “User’s Guide”).
5
In This Book
Specifications Chapter 1 lists the multimeter’s specifications and
describes how to interpret these specifications.
Quick Start Chapter 2 prepares the multimeter for use and helps you
get familiar with a few of its front-panel features.
Menu Tutorial Chapte r 3 introduces you to the front-panel menu and
steps you through several si m p l e menu examples.
Calibration Procedures Chapter 4 provides a detailed desc ript ion of
the multimeter’s calibrations and adjustments.
Theory of Operation Chapter 5 describes each functional block in the
multimeter.
Service Chapter 6 provides guidelines for returning your multimeter
to Agilent for servicing, or for servicing it yourself.
Replaceable Parts Chapter 7 contains a detailed parts list of the
multimeter.
Backdating Chapter 8 describes the procedures involved with back
issues of this manu al .
Schematics Chapter 9 provides the multimeter’s schematics.
If you have questions relating to the operation of the Agilent 34401A,
call 1-800-452-4844 in the United States, or contact your nearest
Agilent Sal es Of fic e .
If your 34401A fails within one year of purchase, Agilent will repair or
replace it free of charge. Call 1-877-444-7278 (“ Agile nt Expr ess”) in th e
United States, or c ontact you r neare st Agilen t Sales O ffice .
6
Contents
Chapter 1 Specifications
DC Characteristics 12
AC Characteristics 14
Frequency and Period Characteristics 16
Genera l I nformation 18
Produ ct Di mensions 19
To Calculate Total Me as urem en t Erro r 20
Interpreting Multimeter Specifications 22
Configuring for Highest Accuracy Measurements 25
Chapter 2 Quick Start
To Prepare the Multim eter for Use 29
If the Multimeter Does N ot Tu rn On 30
To Adjust the Carrying Handle 32
To Measure Voltage 33
To Measure Resistance 33
To Measure Current 34
To Measure Frequen cy (or Period) 34
To Test Continui ty 35
To Check Diodes 35
To Select a Range 36
To Set the Resolution 37
To Make Null (Relative) Measurements 38
To Store Minimum and Maximum Readings 39
To Make dB Measur emen t s 40
To Make dBm Measurements 41
To Trigger the Multimeter 42
To Make dcv:dcv Rat io Me as urem en ts 43
Front-Panel Display For mats 44
To Rack Mount the Multimeter 45
Contents
Chapter 3 Menu Tutorial
Front-Panel Menu Reference 49
A Front-Panel Menu Tutorial 51
Menu Examples 53
7
Contents
Contents
Chapter 4 Calibration Procedures
Agilent Calibration Services 61
Calibration Interval 61
Time Required for Calibration 61
Automating Calibration Procedures 62
Recommended Test Equipment 63
Test Considerations 64
Performance Ver i ficati o n Test s 65
Zero Offset Ver ificat ion 67
Gain V eri fication 69
Optional AC Per for ma nce V erif icat ion Tes ts 72
Calib ra t i on Security C od e 73
Calibration Count 75
Calibration Mes sage 75
Calibration Procedures 76
Aborting a Calibration in Progress 76
Zero Ad j us t ment 77
Gain Adjustment 79
Optional Gain Calibration Procedures 82
Understanding the AC Signal Filter 85
Understanding Resolution 86
Error Message s 89
Chapter 5 Theory of Operation
Block Diagram 93
Front/Rear Selection 94
Function Switching 95
DC Amplifier 96
Ohms Current Source 98
AC Circuit 99
A-to-D Converter 101
Floating Log ic 103
Earth -R e ferenced Log i c 105
Power Supplies 106
Front Panel 107
8
Contents
Chapter 6 Service
Operating Checklist 111
Types of Service Available 112
Repackaging for Shipment 113
Electrostatic Discharge (ESD) Precautions 114
Surface Mount Repair 114
To Replace the Power-Li n e Fuse 114
To Replace The Current Input Fu s es 115
To Connect Pass/Fail Output Signals 115
Troubleshooting Hints 117
Self-Test Pro ced ur es 120
Chapter 7 Replaceable Parts
To Order Replaceable Parts 126
Backdating and Part Changes 126
Replaceable Parts: 34401-66501 (Main Assembly) 127
Replaceable Parts: 34401-66512 (Display Assembly) 133
Replaceable Parts: Agilent 34401A Mainframe 134
Manufacturer’s List 135
Chapter 8 Backdating 137
Chapter 9 Schematics
Mechanical Disassembly 9-3
Component Locator Diagram – Main Board (34401-66501) 9-5
Component Locator Diagram – Front Panel (34401-66512) 9-6
Agilent 34401A Block Diagram 9-7
Front/Rear Selection Schematic 9-8
Function Switching Schematic 9-9
DC Amplifier and Ohms Schematic 9-10
AC Circuit Schematic 9- 11
A/D Converter Schematic 9-12
Floating Logic Schematic 9-13
Earth -R e ferenced Log i c S ch e m a t i c 9-14
Power Supplies Sche matic 9-15
Front-Panel Display Schematic 9-16
Contents
9
Contents
10
1
1
Specifications
Chapter 1 Specific ations
DC Characteristics
DC Characteristics
Function
DC Voltage 100.000 0 mV
Range [ 3 ]
1.000000 V
10.00000 V
100.000 0 V
1000.00 0 V
Test Current or
Burden Voltage
Accuracy Specifications ± ( % of reading + % of range ) [ 1 ]
24 Hour [ 2 ]
23°C
± 1°C
0.0030 + 0.0030
0.0020 + 0.0006
0.0015 + 0.0004
0.0020 + 0.0006
0.0020 + 0.0006
90 Day
23°C
± 5°C
0.0040 + 0.0035
0.0030 + 0.0007
0.0020 + 0.0005
0.0035 + 0.0006
0.0035 + 0.0010
1 Year
23°C ± 5°C
0.0050 + 0.0035
0.0040 + 0.0007
0.0035 + 0.0005
0.0045 + 0.0006
0.0045 + 0.0010
Temperature
Coefficient /°C
0°C – 18°C
28°C – 55°C
0.0005 + 0.0005
0.0005 + 0.0001
0.0005 + 0.0001
0.0005 + 0.0001
0.0005 + 0.0001
Resistance
[ 4 ]
DC Current 10.00000 mA
Continuity 1000.0
Diode Test
[12]
DC:DC Ratio 100 mV
Transfer Accuracy ( typical )
100.0000
1.000000 kΩ
10.00000 kΩ
100.000 0 kΩ
1.000000 MΩ
10.00000 MΩ
100.000 0 MΩ
100.000 0 mA
1.000000 A
3.000000 A
1.00 00 V 1 mA 0.002 + 0.010 0.008 + 0.020 0.010 + 0.020 0.001 + 0.002
to
1000 V
( 24 hour %
Ω
Ω 1 mA 0.002 + 0.030 0.008 + 0.030 0.010 + 0.030 0.001 + 0.002
of range error )
1 mA
1 mA
100
10
µA
5
µA
500 nA
500 nA || 10 M
< 0.1 V
< 0.6 V
< 1 V
< 2 V
2
µA
0.0030 + 0.0030
0.0020 + 0.0005
0.0020 + 0.0005
0.0020 + 0.0005
0.002 + 0.001
0.015 + 0.001
0.300 + 0.010
Ω
0.005 + 0.010
0.01 + 0.004
0.05 + 0.006
0.10 + 0.020
( Input Accuracy ) + ( Reference Accuracy )
Input Accuracy = accuracy specification for the HI-LO input signal.
Reference Accuracy = accuracy specification for the HI-LO reference input signal.
Conditions:
Within 10 minutes and ± 0.5°C.
Within
Following a 2-hour warm-up.
Fixed range b etween 10% and 100% of full scale.
Using 6
Measurements are made using accepted metrology practices.
0.008 + 0.004
0.008 + 0.001
0.008 + 0.001
0.008 + 0.001
0.008 + 0.001
0.020 + 0.001
0.800 + 0.010
0.030 + 0.020
0.030 + 0.005
0.080 + 0.010
0.120 + 0.020
±10% of initial value.
1
⁄2 digit s low resoluti on ( 100 PLC ).
0.010 + 0.004
0.010 + 0.001
0.010 + 0.001
0.010 + 0.001
0.010 + 0.001
0.040 + 0.001
0.800 + 0.010
0.050 + 0.020
0.050 + 0.005
0.100 + 0.010
0.120 + 0.020
0.0006 + 0.0005
0.0006 + 0.0001
0.0006 + 0.0001
0.0006 + 0.0001
0.0010 + 0.0002
0.0030 + 0.0004
0.1500 + 0.0002
0.002 + 0.0020
0.002 + 0.0005
0.005 + 0.0010
0.005 + 0.0020
12
Chapter 1 Specific ations
DC Characteristics
1
Measuring Characteristics
DC Voltage
Measurement Method:
A/D Linearity:
Input Resistance:
0.1 V, 1 V, 10 V ranges
100 V, 1000 V ranges
Input Bias Current:
Inpu t Terminals:
Input Protection:
Resistance
Measurement Method:
Max. Lead Resistance:
(4-wire ohms)
Input Protection:
DC Current
Shunt Resistor:
Input Protection:
Continuity / Diode Test
Response Time:
Continuity Threshold:
DC:DC Ratio
Measurement Method:
Input HI-LO
Refere nc e HI -I np ut LO
Input to Refe ren ce
Measurement Noise Rejection
60 Hz ( 50 Hz ) [ 5 ]
DC CMRR
Integration Time
100 PLC / 1.67s (2s)
10 PLC / 167 ms (200 ms)
1 PLC / 16.7 ms (20 ms)
0.2 PLC / 3 ms (3 ms)
0.02 PLC / 400
µs (400 µs)
[12] Accuracy specifications ar e for th e voltage measured at
the input terminals only. 1mA test current is typical. Variation
in the current source will create some variation in the vol tage
drop ac ross a diode junction.
Continuously integrating, multi-slope III
A/D conv ert e r.
0.0002% of reading + 0.0001% of range
Selectable 10 M
Ω or >10 GΩ [11]
10 MΩ ±1%
< 30 pA at 25°C
Copper alloy
1000 V on all ranges
Selectable 4-wire or 2-wire ohms.
Current source referenced to LO input.
10% of range per lead for 100
ranges. 1 k
Ω per lead on all other ranges.
Ω, 1 kΩ
1000 V on all ranges
Ω for 1A, 3A. 5Ω for 10 mA, 100 mA
0.1
Externally accessible 3A, 250 V fuse
Internal 7A, 250 V fuse
300 samples/sec with audible tone
Adjustable from 1
Ω to 1000 Ω
Input HI-LO / Reference HI-LO
100 mV to 1000 V ranges
100 mV to 10 V ranges (autoranged)
Reference LO to Input LO voltage < 2 V
Reference HI to Input LO voltage < 12V
140 dB
Normal Mode Rejection
60 dB [ 7 ]
60 dB [ 7 ]
60 dB [ 7 ]
0 dB
0 dB
Teflon is a registered trademark of E.I. duPont deNemours and Co.
[ 6 ]
Operating Characteristics [ 8 ]
Additional
Function
DCV, DCI, and
Resistance
System Speeds
Digits
6
6
5
5
4
[ 9 ]
1
⁄
2
1
⁄
2
1
⁄2
1
⁄
2
1
⁄2
Readings/s
0.6 (0.5)
6 (5)
60 (50)
300
1000
Function Change
Range C ha ng e
Autorange Ti me
ASCII readings to RS-232
ASCII readings to GPIB
Max. Internal Trigger Rate
Max. External Trigger Rate to Memory
Max. External Trigger Rate to GPIB
Noise Error
0% of range
0% of range
0.001% of range
0.001% of range
0.01% of range
26/sec
50/sec
<30 ms
55/sec
1000/sec
1000/sec
1000/sec
900/sec
[10]
[10]
Autozero OFF Operation
Follow ing in st ru men t warm- u p at ca l ib rat i on temp er atu re ±1°C
and <10 minutes, add 0.0002% range additional error + 5 µV.
Settling Considerations
Reading settling times are affected by source impedance,
cable dielectric characteristi cs, and input signal changes.
Measurement Considerations
Agilent recommends the use of Teflon
â
or other high-impedance,
low-dielectric absorption wire insulation for these measurements.
[ 1 ] Specifications are for 1-hour warm-up at 61⁄2 digits.
[ 2 ] Relative to calibration s tandards.
[ 3 ] 20% overrange on all ranges, except 1000 Vdc, 3 A range.
[ 4 ] Specifications are for 4-w ire ohms function, or 2-wire
ohms using Ma th Null. Without Math Null, add 0.2
additional error in 2-wire ohms function.
[ 5 ] For 1 kΩ unbala nc e in LO lead .
[ 6 ] For power-line frequency ± 0.1%.
[ 7 ] For power-line frequency ± 1%, subtract 20 dB.
For
[ 8 ] Readings speeds for 60 Hz and ( 50 Hz ) operation,
± 3%, subtract 30 dB.
Autozero Off.
[ 9 ] Speeds are for 41⁄
digits, Dela y 0, A uto ze r o OF F,
2
and Display OFF. Includes measurement and data
transfer over GPIB.
[ 10 ] Add 20 µV for dc volts, 4 µA for dc current, or
20 m
[ 11 ] For these ranges, inputs beyond ±17V are
clamped through 100 k
Ω for resistance.
Ω (typical).
Ω
13
Chapter 1 Specific ations
AC Characteristics
AC Characteristics
Accuracy Spe cificati ons ± ( % of reading + % of range ) [ 1 ]
Function Range [ 3 ] Frequency
True RMS
AC Voltage
[ 4 ]
True RMS
AC Current
[ 4 ]
Additional Low Frequency Errors ( % of reading )
100.000 0 mV
1.00 0000 V
to
750.000 V
1.000000 A
3.00 000 A
Frequency
10 Hz – 20 Hz
20 Hz – 40 Hz
40 Hz – 100 Hz
100 Hz – 200 Hz
200 Hz – 1 kHz
> 1 kHz
3 Hz – 5 Hz
5 Hz – 10 Hz
10 Hz – 20 kHz
20 kHz – 50 kHz
50 kHz – 100 kHz
100 kHz – 300 kHz
3 Hz – 5 Hz
5 Hz – 10 Hz
10 Hz – 20 kHz
20 kHz – 50 kHz
50 kHz – 100 kHz
100 kHz – 300 kHz [6]
3 Hz – 5 Hz
5 Hz – 10 Hz
10 Hz – 5 kHz
3 Hz – 5 Hz
5 Hz – 10 Hz
10 Hz – 5 kHz
AC Filter
Slow Medium Fast
0 0.74 ––
0 0.22 ––
0 0.06 0.73
0 0.01 0.22
0 0 0.18
0 0 0
[6]
[5]
24 Hour [ 2 ]
23°C
± 1°C
1.00 + 0.03
0.35 + 0.03
0.04 + 0.03
0.10 + 0.05
0.55 + 0.08
4.00 + 0.50
1.00 + 0.02
0.35 + 0.02
0.04 + 0.02
0.10 + 0.04
0.55 + 0.08
4.00 + 0.50
1.00 + 0.04
0.30 + 0.04
0.10 + 0.04
1.10 + 0.06
0.35 + 0.06
0.15 + 0.06
Additional Crest Factor Errors ( non-sinewave ) [ 7 ]
90 Day
23°C
± 5°C
1.00 + 0.04
0.35 + 0.04
0.05 + 0.04
0.11 + 0.05
0.60 + 0.08
4.00 + 0.50
1.00 + 0.03
0.35 + 0.03
0.05 + 0.03
0.11 + 0.05
0.60 + 0.08
4.00 + 0.50
1.00 + 0.04
0.30 + 0.04
0.10 + 0.04
1.10 + 0.06
0.35 + 0.06
0.15 + 0.06
Crest Factor
1 – 2
2 – 3
3 – 4
4 – 5
1 Year
23°C ± 5°C
1.00 + 0.04
0.35 + 0.04
0.06 + 0.04
0.12 + 0.05
0.60 + 0.08
4.00 + 0.50
1.00 + 0.03
0.35 + 0.03
0.06 + 0.03
0.12 + 0.05
0.60 + 0.08
4.00 + 0.50
1.00 + 0.04
0.30 + 0.04
0.10 + 0.04
1.10 + 0.06
0.35 + 0.06
0.15 + 0.06
Erro r ( % of r eadi ng )
0.05%
0.15%
0.30%
0.40%
Temperature
Coefficient/°C
0°C – 18°C
28°C – 55°C
0.10 0 + 0.004
0.03 5 + 0.004
0.00 5 + 0.004
0.01 1 + 0.005
0.06 0 + 0.008
0.20 + 0.02
0.10 0 + 0.003
0.03 5 + 0.003
0.00 5 + 0.003
0.01 1 + 0.005
0.06 0 + 0.008
0.20 + 0.02
0.10 0 + 0.006
0.03 5 + 0.006
0.01 5 + 0.006
0.10 0 + 0.006
0.03 5 + 0.006
0.01 5 + 0.006
Sinewave Transfer Accuracy ( typical )
Frequency
10 Hz – 50 kHz
50 kHz – 300 kHz
Error ( % of r ange )
0.002%
0.005%
14
Conditions:
Sinewave input.
Within 10 minutes and ± 0.5°C.
Within ±10% of initia l volt ag e and ±1% of initial frequency.
Following a 2-hour warm-u p.
Fixed range between 10% and 100% of full scale ( and <120 V ).
Using 6
Measur ements are made using accepted metrology practices.
1
⁄2 digit resolution.
Chapter 1 Specific ations
AC Characteristics
1
Measuring Characteristics
Measurement Noise Rejection
AC CMRR
True RMS AC Voltage
Measurement Method:
Crest Factor:
AC Fil ter Bandwidth:
Slow
Medium
Fast
Input Impedance:
Input Protection:
True RM S AC Curr ent
Measurement Method:
Shunt Resistor:
Burden Voltage:
Input Protection:
Settling Conside ration s
Applying >300 V rms (or >1 A rms) will cause self-heating in
signal-c on ditionin g co mp onents. Thes e err o r s are inc lu ded in
the instrument specifications. Internal temperature changes
due to s elf-heating may cause addit ional error on lower ac
voltage ranges. The additional error will be less than 0.02%
of reading and will generally dissipate within a few minutes.
[ 8 ]
70 dB
AC-c ou pled Tr ue R MS – measures
the ac component of input with up
to 400 Vdc of bias on any range.
Maximum 5:1 at full scale
3 Hz – 300 kHz
20 Hz – 30 0 kHz
200 Hz – 300 kHz
1 M
Ω ± 2%, in parallel with 100 pF
750 V rms all ranges
Direct coupled to the fuse and shunt.
AC-coupled True RMS measurement
(measures the ac component only).
0.1
Ω for 1 A and 3 A ranges
1 A range: < 1 V rms
3 A range: < 2 V rms
Exter na lly ac ce ss ib l e 3A, 25 0 V f us e
Internal 7A, 250 V fuse
Operating Characteristics [ 9 ]
[ 10 ]
[ 11 ]
AC Filter
Slow
Medium
Fast
Fast
Fast
5/sec
<0.8 sec
50/sec
50/sec
50/sec
50/sec
50/sec
1
⁄2 digits,
7
Volt-Hz.
Function
Digits
ACV, ACI 6
System Speeds
1
⁄2
1
6
⁄
1
6
⁄2
1
6
⁄
1
6
⁄2
[ 11 ] , [ 12 ]
2
2
Reading/s
7 sec/reading
1
1.6
10
50
Functio n or Ra ng e C ha ng e
Autora ng e Tim e
ASCII readings to RS-232
ASCII readings to GPIB
Max. Internal Trigger Rate
Max. External Trigger Rate to Memory
Max. External Trigger Rate to GPIB/RS-232
[ 1 ] Specifications are for 1-hour warm-up at 6
Slow ac filter, sinewave input.
[ 2 ] Relative to calibration standards.
[ 3 ] 20% overrange on all ranges, except 750 Vac, 3 A range.
[ 4 ] Specifications are for sinewave input >5% of range.
For inputs from 1% to 5% of range and <50 kHz,
add 0.1% of range additional error. For 50 kHz to 100 kHz,
add 0.13% of range.
[ 5 ] 750 Vac ran ge limited to 100 kHz or 8x10
[ 6 ] Typically 30% of reading error at 1 MHz.
[ 7 ] For frequencies below 100 Hz, slow AC filter specified
for sinewave input only.
[ 8 ] For 1 kΩ unbalance in LO lead.
[ 9 ] Maximum reading rates for 0.01% of ac step
addit ional error. Additional settling delay required
when input dc level varies.
[ 10 ] For External Trigger or remote operation using default
settling delay ( Delay Auto ).
[ 11 ] Maximum useful limit with default settling delays defeated.
[ 12 ] Speeds are for 4
1
⁄2 digits, Delay 0, Display OFF, and
Fast AC filter.
15
Chapter 1 Specific ations
Frequency and Period Characteristics
Frequency and Period Characteristics
Accuracy Specifications ± ( % of reading ) [ 1 ]
Function Range
Frequency,
Period [ 4 ]
Additional Low-Frequency Errors ( % of reading )
Transfer Accuracy ( typical )
[ 3 ] Frequency
100 mV
to
750 V
Frequency
3 Hz – 5 Hz
5 Hz – 10 Hz
10 Hz – 40 Hz
40 Hz – 100 Hz
100 Hz – 300 Hz
300 Hz – 1 kHz
> 1 kHz
0.0005 % of reading Conditions:
3 Hz – 5 Hz
5 Hz – 10 Hz
10 Hz – 40 Hz
40 Hz – 300 kHz
Resolution
1
6
⁄2 51⁄2 41⁄2
0 0.12 0.12
0 0.17 0.17
0 0.2 0.2
0 0.06 0.21
0 0.03 0.21
0 0.01 0.07
0 0 0.02
90 Day
24 Hour
23°C ± 1°C
0.10
0.05
0.03
0.006
[ 4 ]
Within 10 minutes and ± 0.5°C.
Within ±10% of initial value.
Following a 2-hour warm-up.
For inputs > 1 kH z and > 100 mV.
Using 6
Measurements are made usi ng accepted metrology practi ces.
[ 2 ]
23°C
± 5°C
0.10
0.05
0.03
0.01
1
⁄2 digit slow resolution ( 1 second gate time ).
1 Year
23°C ± 5°C
0.10
0.05
0.03
0.01
Temperature
Coefficient/°C
0°C – 18°C
28°C – 55°C
0.005
0.005
0.001
0.001
16
Chapter 1 Specific ations
Frequency and Period Characteristics
1
Measuring Characteristics
Frequency and Period
Measurement Method:
Voltage Ranges:
Gate Time:
Settling Considerations
Errors wil l oc cu r wh en at t emp tin g t o meas ur e the f req ue nc y o r
period of an i np ut f ol l owi ng a dc off se t v ol tag e ch an ge . Th e i np ut
blocking RC time constant must be allowed to fully settle ( up to
1 sec ) before the most accurate measurements are possible.
Measurement Considerations
All frequency counters ar e susceptible to error when
measuring low-voltage, low-frequency signals. Shielding
inputs from external noise pickup is critical for minimizing
measurement errors.
Reciprocal-counting technique.
AC-coupled input using the
ac voltage measurement function.
100 mV rms fu ll s ca le to 750 V rm s.
Auto or manual rangin g.
10 ms, 100 ms, or 1 sec
Operating Characteristics [ 5 ]
Function
Frequency,
Period
System Speeds
Digits
1
6
⁄
2
1
5
⁄2
1
4
⁄2
[ 5 ]
Configuration Rates
Autora ng e Tim e
ASCII readings to RS-232
ASCII readings to GPIB
Max. Internal Trigger Rate
Max. External Trigger Rate to Memory
Max. External Trigger Rate to GPIB/RS-232
[ 1 ] Specifications are for 1- hour warm-up at 6
[ 2 ] Relative to calibration standards.
[ 3 ] 20% overrange on all ranges, except 750 Vac range.
[ 4 ] Input > 100 mV. For 10 mV to 100 mV inputs,
multiply % of reading error x10.
[ 5 ] Speeds are for 4
1
⁄2 digits, Delay 0, Display OFF,
and Fast AC filter.
Reading/s
1
9.8
80
14/sec
<0.6 sec
55/sec
80/sec
80/sec
80/sec
80/sec
1
⁄2 digit s .
17
Chapter 1 Specific ations
Gene r a l Information
General In formation
General Specifications
Power Supply:
Power Line Frequency:
Power Consumption:
Operating Environment:
Storag e Env ironment:
Rack Dimensions (HxWxD):
Weight:
Safety:
EMI:
Vibration and Shoc k:
Warranty:
Accessories Included
Test Lead Kit with probes, alligator, and grabber attachments.
User’s Guide, Service Guide, test report, and power cord.
100 V / 12 0 V / 220 V / 240 V
45 Hz to 66 Hz and 360 Hz to 440 Hz.
Automatically sensed at power-on.
25 VA peak ( 10 W avera ge )
Full accuracy for 0
Full accuracy to 80% R.H. at 40°C
-40°C to 70° C
88.5 mm x 212.6 mm x 348.3 mm
3.6 kg (8 lbs)
Designed to CSA 231, UL 1244,
IEC 1010-1 (1990)
CISPR 11, IEC 801,
MIL-461C (data on file)
MIL-T-28800E Type III, Class 5
(data on file)
1 year
°C to 55°C
±10%.
Triggering and Memory
Reading
HOLD Sensitivity:
Samples per Trigge r:
Trigger Delay:
External Trigge r Delay:
External Trigge r Jitter:
Memory:
Math Functions
Null, Min/Max/Average, dB, dBm, Limit Test (with TTL output).
dBm ref e ren ce resi s ta nc es : 50, 75 , 93, 11 0, 12 4, 12 5, 13 5, 15 0,
250, 300, 500, 600, 800, 900, 1000, 1200, or 8000 ohms.
Standard Programming Languages
SCPI (Standa rd C omm ands fo r Pr ogr amm ab le In st ru men t s)
Agilent 3478A Language Emulati on
Fluke 8840A, Fluke 8842A Language Emulation
Remote Interface
GPIB (IEEE-488.1, IEEE-488.2) and RS-232C
This ISM device complies with Canadian ICES-001.
Cet appareil ISM est conforme à la norme NMB-00 1
du Canada.
0.01 %, 0.1% , 1%, or 10% of read ing
1 to 50,000
0 to 36 00 sec ( 10
< 1 ms
< 500
µs
512 readings
µs step size )
18
N10149
Chapter 1 Specific ations
Product Dimensions
Product Dimensions
Product Dimensions
1
103.8 mm
261.1 mm
212.6 mm
379.4 mm
88.5 mm
348.3 mm
TOP
All dimensions are
shown in millimeter s.
19
Chapter 1 Specific ations
To Calculate Total Measurement Error
To Calculate Total Measurement Error
Each specifi ca t i on includes co rrection factors which account fo r err ors
present due to operational limitations of the multimeter. This section
explains these errors and shows how to a pply th em to you r measuremen ts.
Refer to “Interpreting Multimeter Specifications,” starting on page 22,
to get a better understanding of the terminology used and to help you
interpret the multimeter’s specifications.
The multimeter’s accuracy specifications are expressed in the form:
( % of reading + % of range ). In addition to the reading erro r an d ran g e
error, you may need to add additional errors for certain operating
conditions. Check the list below to make sure you include all
measurement errors for a given function. Also, make sure you apply the
conditions as described in the f o otnotes on the specification pages.
• If you are operatin g the m ultim e t er outsi de th e 23° C ± 5°C
temperatur e r ange s pec ified, apply an additional temperature
coefficient error.
• For dc voltage, dc current, and resistance measurements, you may
need to apply an additional reading speed error or autozero OFF error.
• For ac voltage and ac current measurements, you may need to apply
an additional low frequency erro r or crest factor error.
Understanding the “ % of reading ” Error The reading error
compensate s fo r i naccuracies that result from the functi on and range
you select, as well as the input signal level. The reading error varies
according to the input level on the selected range. This error is
expressed in percent of readin g. The following table shows the reading
error applied to the multimeter’s 24-hour dc voltage specification.
Range
10 Vdc
10 Vdc
10 Vdc
Input Level
10 Vdc
1 Vdc
0.1 Vdc
Reading Error
(% of reading)
0.0015
0.0015
0.0015
Reading
Error Voltage
≤ 150 µV
≤ 15 µV
≤ 1.5 µV
20
Chapter 1 Specific ations
To Calculate Total Measurement Error
Understandi ng th e “ % of rang e ” Error The range error compensates
for inaccuracies that result from the function and range you select.
The range erro r con trib u tes a cons t ant er r or , expr esse d as a percen t of
range, independent of the input signal level. The fol low in g ta ble show s
the range error applied to the mul timeter’s 24-hou r dc v oltage speci fication.
1
Rang e
10 Vdc
10 Vdc
10 Vdc
Input Level
10 Vdc
1 Vdc
0.1 Vdc
Range Error
(% of range)
0.0004
0.0004
0.0004
Range
Error Voltage
≤ 40 µV
≤ 40 µV
≤ 40 µV
Total Measurement Error To compute the total measurement error, add the reading error and range error. You can then convert the total measurement error to a “percent of input” error or a “ppm (part-permillion) of input” error as shown below.
% of input error =
ppm of input error =
Total Measur em en t E rr or
Input Signal Level
Total Measur em en t E rr or
Input Signal Level
× 100
× 1,000,000
Error Example Assume that a 5 Vdc signal is input to the multimeter on the 10 Vdc range.
Compute the total measurement error using the 90-day accuracy
specifications:
± (0.0020% of reading + 0.0005% of range).
Reading Error
Range Error
Total Error
= 0.0020%
= 0.0005%
µV + 50 µV
= 100
× 5 Vdc
× 10 Vdc
= 100 µV
= 50
µV
=
± 150 µV
± 0.0030% of 5 Vdc
=
± 30 ppm of 5 Vdc
=
21
Chapter 1 Specific ations
Interpreting Multimeter Specifications
Interpreting Multimeter Specifications
This section is provided to give you a better understanding of the terminology
used and wil l help you in terpre t the mu ltimete r’s spe cificatio ns.
Number of Digits and Overrange
The “number of dig its” specification is the most fundamental, and
sometimes, the most confusing characteristic of a multimeter.
The number of digits is equal to the maximum number of “9’s” the
multimeter can measure or display. This indicates the number of full
digits. Most multimeters have the ability to overrange and add a partial
1
or “
⁄
” digit.
2
For example, the Agilent 34401A can measure 9.99999 Vdc on the 10 V
range. This represents six full digits of resolution. The multimeter can
also overrange on the 10 V range and measure up to a maximum of
12.00000 Vdc. This corresponds to a 6
overrange capability.
1
⁄
-digit measurement with 20%
2
Sensitivity
Sensitivity is the minimum level that the multimeter can detect for a
given measurement. Sensitivity defines the ability of the multimeter to
respond to small changes in the input level. For example, suppose you
are monitoring a 1 mVdc signal and you want to adjust the level to
within
measurement w ould re quire a multim eter with a s ensitivit y of at least 1
You could use a 6
You could also use a 4
For ac voltage and ac current measurements, note that the smallest
value that can be measured is different from the sensitivity. For the
Agilent 34401A, these functions are specified to measure down to 1% of
the selected range. For example, the multimeter can measure down to
1 mV on the 100 mV range.
22
±1 µV. To be able to respond to an adjustme nt this smal l, this
1
⁄
-digit multimeter if it has a 1 Vdc or smaller range.
2
1
⁄
-digit multimeter with a 10 mVdc range.
2
µV.
Chapter 1 Specific ations
Interpreting Multimeter Specifications
Resolution
Resolution is the numeric ratio of the maximum displayed value divided
by the minimum dis pla yed valu e on a selec t ed ra nge. Reso lution is
often expressed in percent, parts-per-million (ppm), counts, or bits.
For example, a 6
1
⁄
-digit multimeter with 20% overrange capability can
2
display a measurement with up to 1,200,000 counts of resolution.
This corresponds to about 0.0001% (1 ppm) of full scale, or 21 bits
including the sign bit. All four specifications are equivalent.
Accuracy
Accuracy is a measure of the “exactness” to which the multimeter’s
measurement uncertainty can be determined relative to the calibration
reference used. Absolute accuracy includes the multimeter’s relative
accuracy specification plus the known error of the calibration reference
relative to national standards (such as the U.S. National Institute of
Standards and Technology). To be meaningful, the accuracy specifications
must be accompanied with the conditions under which they are valid.
These conditions should include temperature, humidity, and time.
1
There is no standar d co nv en ti on am on g mul tim eter man u fac t u re rs for
the confidence limits at which specifications are set. The table be lo w
shows the probability of non-conformance for each specificatio n with the
given assumptions.
Specification
Criteria
Mean
± 2 sigma
Mean
± 3 sigma
Mean
± 4 sigma
Probability
of Failure
4.5%
0.3%
0.006%
Variations in performance from reading to reading, and instrument to
instrument, decrease for increasing number of sigma for a given
specification. This means that you c an a chi eve greater act ual m easurement
precision for a specific accuracy specification number.
The Agilent 34401A is designed and tested to meet performance better
than mean
±4 sigma of the published accuracy specifications.
23
Chapter 1 Specific ations
Interpreting Multimeter Specifications
Transfer Accuracy
Transfer accuracy refer s to the error introduced by the multimeter
due to noise and short-term drift. This error becomes apparent when
comparing two nearly-equal signals for the purpose of “tran sf erring”
the known ac cur a c y of one dev ic e to the ot h er .
24-Hour Accuracy
The 24-hour accuracy specification indicates the multimeter’s relative
accuracy over its full measurement range for short time intervals and
within a stable environment. Short-term accuracy is usually specified
for a 24-hour period and for a
±1°C temperatu r e ran g e.
90-Day and 1-Year Accuracy
These long-term accuracy specifications are valid for a 23°C ± 5°C
temperature range. These specifications include the initial calibratio n
errors plus the multimeter’s long-term drift errors.
Temperature Coefficients
Accuracy is usually specified for a 23°C ± 5°C temperature range.
This is a common temperature range for many operating environments.
You must add additional temperature coefficient errors to the accuracy
specification if you are operating the multimeter outside a 23°C ± 5°C
temperature range (the specification is per °C).
24
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